The present invention relates generally to defibrillators. In particular the present invention relates to a defibrillator having a battery with a memory component for use with the defibrillator to indicate the status of the battery.
Cardiac arrest, exposure to high voltage power lines and other trauma to the body can result in ventricular fibrillation which is the rapid and uncoordinated contraction of the myocardium. The use of external defibrillators to restore the heart beat to its normal pace through the application of an electrical shock is a well recognized and important tool in resuscitating patients. External defibrillation is used in emergency settings in which the patient is either unconscious or otherwise unable to communicate.
Automated external defibrillators (AEDs) are used by first responders such as police officers, paramedics and other emergency medical technicians to resuscitate cardiac arrest patients. The AEDs carried by these technicians must be quickly operational after powering up and must not provide false alarms that might delay rescue. In a high stress situation of cardiac arrest, the technician must be able to rely on the operability of the AED. Studies have shown that the chances of successfully resuscitating the patient decreases approximately ten percent per minute following cardiac arrest.
Accordingly, constant readiness of the AED is imperative. This readiness must extend to the power source of the AED, which is commonly a lithium battery. Lithium batteries are characterized by the delivery of a relatively constant voltage over a period of time which then terminates abruptly with little or no warning as the battery loses its ability to deliver energy. When using a defibrillator, an abrupt failure of the power source of a defibrillator without warning is unacceptable. Accordingly, some AEDs include the capability to perform a self test to insure that the battery has energy and that the AED can properly use that energy to deliver a shock. However, these self tests do not reveal the amount of energy left in the battery. Knowing the remaining capacity of the battery is helpful for determining how many more rescues can be performed with an AED, for determining when to replace a battery, and above all, for avoiding battery failure during use of an AED.
A defibrillator battery of the present invention includes at least one battery cell, a housing surrounding the at least one battery cell, and a memory connected to the at least one battery cell. In a preferred embodiment, the memory is positioned inside of the housing that surrounds the at least one battery cell. The defibrillator battery can be used with a defibrillator of the present invention, which includes a battery status indicator which communicates with the defibrillator battery to indicate the status of the defibrillator battery.
A method of determining the defibrillator battery status using the defibrillator battery and associated battery status indicator enables an operator to always determine the remaining charge of the battery and to determine when to replace the battery. This defibrillator battery, and associated battery status indicator, insures constant readiness of the AED for defibrillating a patient by preventing defibrillator failure due to a reduced charge battery.